1 files changed, 20 insertions, 11 deletions

diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index c0164441ab92..28185ad18df3 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -1617,6 +1617,15 @@ static void rcu_idle_count_callbacks_posted(void)
 #define RCU_IDLE_GP_DELAY 4             /* Roughly one grace period. */
 #define RCU_IDLE_LAZY_GP_DELAY (6 * HZ) /* Roughly six seconds. */
 
+static int rcu_idle_flushes = RCU_IDLE_FLUSHES;
+module_param(rcu_idle_flushes, int, 0644);
+static int rcu_idle_opt_flushes = RCU_IDLE_OPT_FLUSHES;
+module_param(rcu_idle_opt_flushes, int, 0644);
+static int rcu_idle_gp_delay = RCU_IDLE_GP_DELAY;
+module_param(rcu_idle_gp_delay, int, 0644);
+static int rcu_idle_lazy_gp_delay = RCU_IDLE_LAZY_GP_DELAY;
+module_param(rcu_idle_lazy_gp_delay, int, 0644);
+
 extern int tick_nohz_enabled;
 
 /*
@@ -1696,10 +1705,10 @@ int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies)
         }
         /* Set up for the possibility that RCU will post a timer. */
         if (rcu_cpu_has_nonlazy_callbacks(cpu)) {
-                *delta_jiffies = round_up(RCU_IDLE_GP_DELAY + jiffies,
-                                          RCU_IDLE_GP_DELAY) - jiffies;
+                *delta_jiffies = round_up(rcu_idle_gp_delay + jiffies,
+                                          rcu_idle_gp_delay) - jiffies;
         } else {
-                *delta_jiffies = jiffies + RCU_IDLE_LAZY_GP_DELAY;
+                *delta_jiffies = jiffies + rcu_idle_lazy_gp_delay;
                 *delta_jiffies = round_jiffies(*delta_jiffies) - jiffies;
         }
         return 0;
@@ -1805,11 +1814,11 @@ static void rcu_prepare_for_idle(int cpu)
                 if (rcu_cpu_has_nonlazy_callbacks(cpu)) {
                         trace_rcu_prep_idle("User dyntick with callbacks");
                         rdtp->idle_gp_timer_expires =
-                                round_up(jiffies + RCU_IDLE_GP_DELAY,
-                                         RCU_IDLE_GP_DELAY);
+                                round_up(jiffies + rcu_idle_gp_delay,
+                                         rcu_idle_gp_delay);
                 } else if (rcu_cpu_has_callbacks(cpu)) {
                         rdtp->idle_gp_timer_expires =
-                                round_jiffies(jiffies + RCU_IDLE_LAZY_GP_DELAY);
+                                round_jiffies(jiffies + rcu_idle_lazy_gp_delay);
                         trace_rcu_prep_idle("User dyntick with lazy callbacks");
                 } else {
                         return;
@@ -1861,8 +1870,8 @@ static void rcu_prepare_for_idle(int cpu)
         /* Check and update the ->dyntick_drain sequencing. */
         if (rdtp->dyntick_drain <= 0) {
                 /* First time through, initialize the counter. */
-                rdtp->dyntick_drain = RCU_IDLE_FLUSHES;
-        } else if (rdtp->dyntick_drain <= RCU_IDLE_OPT_FLUSHES &&
+                rdtp->dyntick_drain = rcu_idle_flushes;
+        } else if (rdtp->dyntick_drain <= rcu_idle_opt_flushes &&
                    !rcu_pending(cpu) &&
                    !local_softirq_pending()) {
                 /* Can we go dyntick-idle despite still having callbacks? */
@@ -1871,11 +1880,11 @@ static void rcu_prepare_for_idle(int cpu)
                 if (rcu_cpu_has_nonlazy_callbacks(cpu)) {
                         trace_rcu_prep_idle("Dyntick with callbacks");
                         rdtp->idle_gp_timer_expires =
-                                round_up(jiffies + RCU_IDLE_GP_DELAY,
-                                         RCU_IDLE_GP_DELAY);
+                                round_up(jiffies + rcu_idle_gp_delay,
+                                         rcu_idle_gp_delay);
                 } else {
                         rdtp->idle_gp_timer_expires =
-                                round_jiffies(jiffies + RCU_IDLE_LAZY_GP_DELAY);
+                                round_jiffies(jiffies + rcu_idle_lazy_gp_delay);
                         trace_rcu_prep_idle("Dyntick with lazy callbacks");
                 }
                 tp = &rdtp->idle_gp_timer;